Draft gear



D. F. SPROUL DRAFT GEAR May 23, 1,939.

3 Sheets-Sheet l Filed Jan. 14, 1937 W IMI N,

May 2K3', 1939. D. F. sPRoUL DRAFT GEAR 3 Sheets-Sheet 2 Filed Jan. 14, 1937 Patented May 23, 1939 PATENT OFFICE f DRAFT GEAR Donald F. Sproul, Chicago, Ill., assigner to Cardwell-Westinghouse Company, a corporation of Delaware Application January 14, 1937, Serial No. 120,566

14 Claims.

' f .,wedging mechanism.

A further object of the invention is the provision of a n ew and improved draft gear having a novel arrangement of friction surfaces for the l friction and wedging mechanism.

Another object of the invention is the provisiony of a draft gear having a new and improved arrangement of friction surfaces and wedging mechanism together with novel means for positively relieving the wedge members upon release of the gear. l

A further object of the invention is the provision'of means for holding the wedging mechanism in perfect alignment and for preventing skewing of any of'its parts.

A still further object of the invention is the provision of a new and improved draft gear that is comparatively inexpensive to manufacture, ef#- cient in use, positive in release after compres- ?sion, and that is simpleand' rugged in construc- `tion.

Other and further objects and advantages of the invention will appear from the following description taken in connection with the accompanying drawings in which:-

Fig. 1 is a horizontal section on a portion oi` a railway car showing the invention in position thereon, the wedge mechanism being taken on the lines I-I of Fig. 6 and I-I of Fig. 7;

Fig. 2 is a side elevation of the gear with parts broken away and parts in section;

Fig. 3 is a side elevation of one of the wedge members;

Fig. 4 is a section on 1ine,4-4 of Fig. l; Fig. 5 is an elevation of the forward end of 40, the gear;

Fig. 6 is a section on line 6 6 of Fig. 1; Fig. 'l is a section on line 'I--l of Fig. 1; Fig. 8 is a perspective view of the spring fol- Ilower;

4.51:` Fig. 9 is a perspective view of one of the frictionA shoes;

Fig. 10` is a perspective view of the inner wedge member;

Fig. 11 is a perspective view ofthe outer wedge .jmemben and Fig. 12 ls a perspective view of one of the 'friction blocks. Referring now to the drawings, the reference character Il) designates theunderframing of a 55,;rai1way carv having the center sills II and I2,

which are provided with the draft lugs I3 and I4 and the buff lugs I5 and I6. The gear, which is designated generally lby the reference char` acter I1, is positioned between the center sills and between the buff and draft lugs in the usual 5l manner. If desired, a follower I8, inserted between the draft lugs and the gear, may be em- `ployed. The gear is embraced by a draft yoke yIll as is usual in such constructions. 'Ihe draft yoke is connected to the coupler 2| in any suitable manner. Since the details of the draft yoke, coupler butt and the arrangement of the lugs on the center sills are of the usual or well-known construction, it is not thought necessary to further illustrate or describe the same. 15 The draft gear comprises a casing 22, which is open at one end, and has a chamber 23 arranged axially thereof. The casing is angular in cross-section and in the form shown, is an octagon. Suitable reinforcing ribs and members 20,

are provided on the exterior for strengthening the structure. In the form shown, a boxlike reinforcing member 24 is provided at each side of the gear. This structure is hollow and extends the full length of the gear casing, as shownr in 25 Fig. 1 of the drawings. By means off this ar' rangement, the strengthr of the casing is materially increased without very materially increasing the weight of the gear. The interior chamber 23 of the gear has an angular wall and in 30 the form shown, the walls form an Octagon as shown in Figs. 4 and 7. Internal ribs 20 on the casing may be employed for positioning the springs, if desired. These ribs will also strengthen the casing. 35 The wedging and friction mechanism for the gear is mounted in what, for convenience of description, will be termed the outer end thereof, as shown in Figs. 1 and 2. It comprises a plurality of friction blocks 25, see Figs. 1 and 12, 40 each of which has an outer fiat wedging face 26 and an inner fiat wedging face 21 arranged opposite tothe wedging face 26. The wedging face 26 of each block is adapted to engage a corresponding wedging face 28 on an outer wedge or 45 thrust member 29. Inthe form of the construction selected to illustrate one embodiment of the invention, four wedges 25 are used and the wedge member 29 is provided with four inclined faces 28 for cooperating with the wedging surfaces 26 50 of the four wedges 25, respectively.

'Ihe wedging member 29 is provided with an axial extension 3| which extends axially inwardly` through an inner wedge member 32, Figs. 1

and 10. The wedge member A32 is provided on its 55 l outer surface with four wedge faces 33, Fig. 3, which are adapted to be engaged by corresponding-wedge faces 21 of the friction blocks 25. The inner wedge member 32 is also provided 5 with a plurality of wedging faces 34 which face inwardly and laterally. Any two adjacent faces 34 of the wedge member 32 form a dihedral angle, the apex 34a of which is in a plane bisecting the opposite face 33. In other words, in the form shown, these wedge faces 34 are angularly spaced 45 from the wedge faces 33 as clearly shown in Figs. 2 and 3. By means of this arrangement, the overall length of the gear wedging mechanism is materially shortened without decreasing the area of the surfaces of the friction faces. It will be seen from an inspection of Figs. 2 and 3 that if the wedge faces 34 were directly opposite the wedge faces 33, the former would not have their present area. The member 32 is provided with an axial projection 35 which spending wedge surfaces 39 of a plurality of friction shoes 4|. Each of the friction shoes 4| is provided with a plane wedge surface 42, Fig. 9, which is adapted in turn to engage the corresponding wedge face 34 on the inner wedge member 32.

In the form of the construction shown, there are four of the friction shoes 4| and the wedge faces 39 and 42 of these shoes engage the four wedging faces 38 and 34, respectively, of the "'spring follower 31 and the wedge member 32.

'I'he outer surfaces of each of the friction shoes 4| and the outer surfaces of each of the friction b1ocks`25 are angular as shown at 43 and 44, re-

spectively, Figs. l, 9 and 12. The surfaces 43 and 40i44 correspond to the angles formed by two adjacent sides of the inner periphery of the draft gear housing 22. surfaces 43 and 44 ofthe shoes and blocks, each form a dihedral angle and each frictionally en- 457i gages two adjacent faces of the walls ofthe casing, Fig. 2. By means of this arrangement, the shoes and friction blocks are prevented from skewingj This is an important feature of the invention in that it insures smooth operation of the parts during both compression and release. Furthermore, since the radial pressure is substantially the same all around the casing, the latter is not so likely to become distorted as where the wedges are on two opposite sides only. Preferably, it tapers slightly toward the closed end whereby the wedges are more readily set up and the release is more prompt.

Interposed between the friction shoes and the wall of the casing are wear plates or friction eleoogments 45 which are secured in position in any suitable manner as by engaging in a suitable recess 46 as shown more clearly in Fig. 1 of the drawings. Each of these plates is angular and in the construction shown, each forms a dihedral angle of 135 to correspond with the angles` formed by the inner walls of the casing.

Suitable means are provided for resiliently resisting the inward movement of the wedging and friction mechanism. As shown, a plurality of springs, concentrically arranged, are employed for this purpose. The outer spring 41 seats against the end wall 48 of the casing and atY its opposite end is seated against the spring seat 31, see Fig, 1. The intermediate spring 49 is seated -`vat one end against the bottom of the casing and In other words, the angularv its other end is seated against the inner end of the projection 35 of the wedge member 32 while the inner spring 5| is seated at one end against the bottom of the casing and its other end is seated against the extension 3| of the Wedge member 2S. It will thus be seen that after the gear is compressed, the springs 5| and 49 will positively release the wedging members.

A bolt 52, extending through the hollow outer wedge member 29, its projection 3| and through a depressed portion 53 and seated in said hollow wedge member and in said depression, may be employed, if desired, to retain the springs under initial pressure and also to hold the parts in assembled relation.

In the operation of the device, when the gear is compressed, the wedge or thrust member engages the friction blocks, forcing them forwardly against the pressure of the springs. This resistance to the forward movement of theseblocks will cause the outer wedge element to force the blocks radially outwardly7 into frictional contact with the wear plates. The friction shoes will likewise be forced into frictional contact with these angular wear plates by the inner wedge member. Upon release, the inner spring 5I, acting directly on the extension 3l of the outer wedge member 29, will positively release this member from its wedging action. Likewise, the inner wedge member 32 will be positively released, thus insuring a prompt release of the gear and insuring against sticking of the parts.

It will be noted that the wedging faces of both the blocks and shoes will tend to force those members radially outwardly into frictional contact with the angular friction faces of the casing. This arrangement will force the blocks and shoes into those angles when the gear isV compressed thereby insuring against even the possibility of skewing of either the blocks or shoes.

It is thought from the foregoing taken in connection with theaccompanying drawings that the construction and operation of my device will be apparent to those `skilled in the art and that changes in size, shape, proportion and details, of` construction may be made without departing from the spirit and scope of the appended claims.

I claim as my invention: f

l.. In a draft gear, a casing having interior angular friction walls, angular friction plates for said Walls, a set of friction blocks each having an angular friction face for engaging the angular face of a corresponding wear plate., a set of friction shoes having friction faces arranged at an angle to each other engaging said wear plates,v

said shoes being partially rotated relative to said blocks, an inner wedge. member having wedge faces engaging said shoes and blocks, said niember having a hollow axial projection, an outer wedge member said outer wedge memberA having an extension extending into said projection, a plurality of springs engaging respectively said projection and extension, a spring follower enn gaging said shoes, and a spring engaging said follower.

2. In a draft gear, a casing having afplurality of friction planar faces on its inner surface, friction shoes each having two faces for engaging two adjacent friction faces on said casing, a plurality of friction wedge blocks each having two friction faces engaging two adjacent faces of said casing, a wedging member between said shoes and blocks having wedging faces engaged by faces on said shoes and blocks, the wedging faces of one side of said wedging member being spaced circumferentiall'y from those of the other side thereof, whereby said blocks, wedge members and shoes willv occupy` a minimum of length in said-casing, a thrust member, and spring means for independently resisting inward movement ofv saidr 'thrus'tf'memben shoes: and blocks and for returning the parts to normal position after release of said gear.

'3 In a draft gear, a casing having an inner Octagon bearing surface, a set of friction shoes and a set of friction blocks each having two frictionsurfaces; engagingtwo adjacent surfaces of said octagon, a'wedge member between said sets, a:l thrust member engaging said blocks, said wedge member-having a friction surface on one side for engagingafrictionV surface on a corresponding bloclgrg and, a; surface on its other'side for engagingj a single friction surface on an adjacent shoe, theglast-named friction surfaces on. said shoes and blocks beingspaced angularly, said wedge member and thrustmember having inwardly extending projections,.means including a spring for each ,projection for resisting the inward movement` of said Wedge and thrust members, and spring meansY engaging. v,the shoesk for returning the parts to inoperative position after release.

4..,In. adraftgear, a casing having an octagon innerr surface, four friction plates each angular in cross section engaging two of said surfaces, four friction shoes each having two adjacent friction faces engaging the two friction faces of an adjacent friction plate, four friction blocks each having two adjacent friction faces engaging a face'on each of two adjacent friction plates, a wedge member between said blocks and shoes, and means including springs and a wedge element for resisting inward movement of said shoes and blocks when said gear is compressed and for restoring the parts to normal position after release, one of said springs engaging said wedge member, one engaging said friction blocks, and another independently resisting the inward movement of said shoes. i

5. In a draft gear, a wedge element comprising a body portion having a head and a cylindrical extension, said head having a plurality of wedging faces on one side and a plurality of wedging faces on the other side, the wedging faces on one side being spaced angularly from those on the opposite side whereby a maximum amount of -wedging surface is obtained in a minimum of axial length of said element.

6. In a draft gear, acasing polygonal in crosssection and having a plurality of friction faces, a set of friction shoes each having a plurality of friction surfaces engaging the friction faces of said casing, a set of friction blocks each having a plurality of friction surfaces engaging a plurality of friction faces of said casing, a Wedge member having inner and outer wedge faces, the outer faces engaging corresponding wedging .faces on said friction blocks and the inner faces lengaging corresponding wedging faces on said friction shoes, a thrust member having a wedging face for each block, a spring seat for engag- 7. A friction block for use in a draft gear comv prising ya body portion provided with an axial extension having its outer surface provided with two friction 'faces forming a dihedral angle and having a planar wedging face on each end there;

of,fsaid wedging faces converging inwardly.

8. In a draft gear, a casing having a plurality of plane friction surfaces, a plurality of wedge blocks, each block having a plurality of plane friction surfaces for engaging a plurality of the friction surfaces of said casing, each block having an inner and an outer plane wedge face, an outer wedge member having a wedge face for each block for forcing said blocks inwardly on the compression of the gear, an inner wedge member having an outer wedging face for each inner plane wedge face on said blocks, a like number of inner wedging faces angularly spaced 45 from the outer wedging faces, respectively, a friction shoe for each inner wedging face, and means including friction elements and a plurality of springs for resisting the compression of said gear.

9. In a draft gear, a casing having interior angularly arranged friction faces, angular wear plates secured kto said faces, sets of friction blocks and shoes, each block and shoe having two faces engaging said angular wear plates, a wedging member between said blocks and shoes, said member having wedging faces engaging the adjacent faces of said shoes rand blocks, the wedging faces engaging said shoes being spaced circumferentially from those engaging said' blocks, a thrust member engaging said blocks for forcing the same radially outwardly of, and longitudinally inwardly of, said casing, and three concentrically arranged springs for positively and independently moving said thrust member, wedging member and shoes to normally released position after compression.

10. In a draft gear, a casing having an interior polyhedral friction surface, inner and outer Wedge members, friction blocks each having two friction faces arranged at an angle engaging two angularly arranged faces on said casing, each of said friction blocks having only two wedging faces each engaging a separate wedge member, said inner and outer wedge members having concentric, inwardly extending projections terminating substantially the same distance from the adjacent end of the gear, a plurality of friction shoes engaging said casing and inner wedging member, a spring seat engaging said shoes and extending about the inner end of said projections, and springs engaging the end of said casing opposite the wedge members and having their inner ends respectively engaging said seat and projections for individually resisting the inward movement of said seat and wedging members.

11. In a draft gear, a casing having a plurality of angular friction surfaces, friction shoes engaging lsaid surfaces, friction block members engaging said surfaces, a wedge member between said shoes and block members, each block member engaging friction surfaces on said casing that are engaged by two adjacent shoes whereby the length of the block members and shoe assembly is a minimum, a thrust member having wedging faces engaging said block members, a spring seat having wedging faces engaging said shoes, and resilient elements engaging said thrust member, wedge member and spring seat, respectively, for returning the same to normal position after compression of said gear, said resilient elements being located at one end of said casing and being of substantially the same length.

12. In a draft gear, a casing, a plurality of contiguous plane friction surfaces arranged at an angle to each other within said casing, a plurality of friction blocks within said casing, each of said blocks having a pair of plane friction surfaces for frictionally engaging two of said contiguous friction surfaces, an outer thrust member having a wedging engagement with said blocks, an inner wedging member having a wedging engagement with said blocks, shoes frictionally engaging said casing and having a wedging engagement with said wedging member, a follower engaging said shoes, said thrust and vwedging members having extensions extending through an opening in said follower, and three concentric springs engaging said follower and said thrust and wedge members, respectively.

13. In a draft gear, a casing polygonal in crosssectio-n, a plurality of sets of friction members frictionally engaging the angular interior walls of said casing, a thrust element having wedging faces for engaging one set of said members for forcing the same longitudinally and laterally of saidcasing when said gear is compressed, a second set of friction members, a wedging element between said two sets of friction members, said elements having extensions, a spring seat surrounding said elements, and three springs of substantially the samelength engaging said seat and extensions, respectively, for resisting the inward movement of said elements and members and for'restoring the parts to normal position after release.

14. In a draft gear, a casing, a plurality of contiguous friction surfaces arranged at an angle to each other within said casing, a set of friction shoes within said casing, each of said shoes having a pair of friction surfaces for frictionally'engaging two of said contiguous friction surfaces, angular friction plates secured to the inner walls of said casing against which said shoes engage, a thrust member engaging said shoes for forcing the same radially outward when the gear is compressed, a second set of friction shoes engaging said plates, each shoe of said second set engaging two of said contiguous surfaces, said last-named surfaces. being engaged by two shoes of the first-named set, a wedge member between said sets of shoes and having wedging faces engaging corresponding wedging faces on said shoes, a spring engaging said thrust member for resisting its inward movement and forreleasing the same upon release of the gear, a second spring for engaging said wedge member resisting its inward movement longitudinally of the gear, and a third spring for resisting the inward movement of Vsaid second set of shoes longitudinally of the gear.

Y DONALD F. SPROUL. 

